scholarly journals The Effect of Chemical Composition of Ultramafic and Mafic Aggregates on Their Physicomechanical Properties as well as on the Produced Concrete Strength

Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 406
Author(s):  
Paraskevi Lampropoulou ◽  
Petros Petrounias ◽  
Panagiota Giannakopoulou ◽  
Aikaterini Rogkala ◽  
Nikolaos Koukouzas ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Mechanical Strength ◽  
Concrete Strength ◽  
Physicomechanical Properties ◽  
International Standards ◽  
Engineering Properties ◽  
Mafic Rocks ◽  
Geochemical Index ◽  
Group I ◽  
Ga Index

This study examines how the chemical composition of ultramafic and mafic rocks effects their physicomechanical properties and therefore how influences the concrete strength of the produced concrete specimens. For this scope, ultramafic (Group I) and mafic rocks (Group II) derived from the Veria–Naousa and Edessa ophiolite complexes (Greece) were selected in order to identify their chemical composition and their engineering properties according to international standards. Additionally, representative rocks were used as concrete aggregates in order to produce concrete specimens, whereas their mechanical strength was calculated. A geochemical index (Ga) was proposed and correlated with the engineering properties of the examined rocks as well as with the widely used alteration degree LOI (loss on ignition). Correlation diagrams between engineering properties and the proposed geochemical index (Ga) have showed that these properties were strongly influenced by the alteration processes expressed via Ga index. More particularly, mainly serpentine in ultramafic and chlorite in mafic rocks, minerals indicators for the alteration of ultramafic and mafic rocks, respectively, seem to determine their engineering properties. Concerning the mechanical strength of the produced concrete specimens, the results have showed that the increasing values of Ga index negatively effect concrete strength.

scholarly journals Effect of Using Different Rations in Nutrition of High-Productive Cows on Milk Quantity and Quality

2015 ◽  
Vol 15 (2) ◽  
pp. 185
Author(s):  
Goce Cilev ◽  
Živko Gacovski ◽  
Biljana Petrovska ◽  
Jovan Stojković
Keyword(s):  
Chemical Composition ◽  
Milk Production ◽  
Milk Fat ◽  
Dry Matter ◽  
Control Group ◽  
Daily Production ◽  
Group I ◽  
Production Increase ◽  
High Level ◽  
Experimental Group

This paper shows the results of production and chemical compo­sition of cow’s milk on a farm MILKO-HF, Prilep, R. Macedonia with capacity of 100 cows of Holstein-Frisian breed divided into two groups (control and experimental). In control group I which was fed in a standard way of nutrition (ration used on the farm), average daily production of milk per cow ws 22.49 kg with the following chemical composition of milk: average daily content of milk fat is 3.75%, protein 3.57%, lactose 4.65%, nonfat dry matter 9.56% and total dry matter 13.31%. In experimental group II which were fed with the ration according to normatives, average daily production of milk per cow is 24.04 kg with the following chemical composition of milk: average daily content of milk fat is 3.99%, protein 3.57%, lactose 4.65%, non-fat dry matter 9.58% and total dry matter 13.57%. The obtained results show the increase in milk production for 1.55 kg-6.89% and better chemical composition of milk in the experimental group of cows. Thus, dry matter was increased from 13.31% to 13.57%-1.95%, milk fat content from 3.75% to 3.99%-6.4%, nonfat dry matter from 9.56% to 9.58%-0.21%, while the content of protein and lactose stayed on equal level. It was determined that the normed nutrition has influenced on production increase and better chemical composition of milk without unnecessary spent high level of nutrient i.e. nutrition of cows according to recommended normative.

scholarly journals Decorative concrete on white cement: resource provision, technology, properties and cost-effectiveness

2018 ◽  
Vol 212 ◽  
pp. 01023 ◽  
Author(s):  
Vasily Vorobchuk ◽  
Maria Matveeva ◽  
Artem Peshkov
Keyword(s):  
Cost Effectiveness ◽  
Chemical Composition ◽  
Raw Materials ◽  
Special Kind ◽  
Physicomechanical Properties ◽  
Industrial Wastes ◽  
Environmental Friendliness ◽  
White Cement ◽  
The Cost ◽  
Experimental Researches

Decorative concrete refers to a special kind of concrete. Products made of decorative concrete must meet, in addition to the increased requirements for appearance, certain architectural expressiveness and also certain indicators for strength, durability, and environmental friendliness. In addition, one should strive to reduce the cost of both decorative concrete and products made of such concrete. The analysis is carried out, experimental researches of qualitative indicators of industrial man-caused wastes are also studied: carbide lime, fluoride, sludge-lignin, their material and chemical composition. The possibility of using the analyzed industrial wastes as raw materials for production of white and color cements is established. The physicomechanical properties of the obtained cements and decorative concretes on their basis are studied, the economic efficiency of the proposed technology is determined.

scholarly journals Seasonal and Circadian Rhythm of a 1,8-Cineole Chemotype Essential Oil of Calycolpus goetheanus From Marajó Island, Brazilian Amazon

2020 ◽  
Vol 15 (6) ◽  
pp. 1934578X2093305
Author(s):  
Edimara L. dos Santos ◽  
Ananda M. Lima ◽  
Vilmara Fabrícia dos S. Moura ◽  
William N. Setzer ◽  
Joyce Kelly R. da Silva ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Chemical Composition ◽  
Rainy Season ◽  
Brazilian Amazon ◽  
Dry Season ◽  
Chemical Compositions ◽  
Flame Ionization ◽  
Group I ◽  
Marajó Island ◽  
Ionization Detectors

Chemical composition of essential oils (EOs) of Calycolpus genus have been reported in the literature. However, there is only 1 report about volatile profile from Calycolpus goetheanus. This work aims to evaluate the seasonal and circadian influences on EO composition and yield of C. goetheanus collected in Marajó Island, Brazilian Amazon. For the circadian study, the leaves were collected in January (rainy season) and July (dry season) every 3 hours during a period of 15 hours. The EOs were obtained by hydrodistillation and their chemical compositions analyzed by gas chromatography coupled to mass spectrometry and flame ionization detectors. The major compound identified in all EO samples was 1,8-cineole with amounts ranged from 14.4% (January, 6 am) to 33.0% (July, 3 pm). The highest average of 1,8-cineole was obtained during circadian study of the dry season (25.5% ± 5.8%) and the lowest during the circadian study of the rainy season (15.6% ± 1.5%). The multivariate analysis grouped the samples into 2 different groups: Group I characterized by the lowest amounts of 1,8-cineole (16.0%-18.7%), and Group II characterized by a higher content of 1,8-cineole (24.0%-33.0%). The oil yield and chemical composition did not show relationship with climate parameters (solar radiation, humidity, and temperature). Therefore, there was only quantitative variability in the EOs compositions during the circadian rhythm evaluated on dry and rainy seasons.

scholarly journals Bitumen and Bitumen Modification: A Review on Latest Advances

2019 ◽  
Vol 9 (4) ◽  
pp. 742 ◽  
Author(s):  
Michele Porto ◽  
Paolino Caputo ◽  
Valeria Loise ◽  
Shahin Eskandarsefat ◽  
Bagdat Teltayev ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Chemical Structure ◽  
Warm Mix Asphalt ◽  
Industrial Applications ◽  
The State ◽  
Engineering Properties ◽  
Bituminous Materials ◽  
Compatibility Of Polymers ◽  
Bitumen Modification

This synthesis explores the state-of-the-knowledge and state-of-the-practice regarding the latest updates on polymer-modified bitumens (PmBs). The information in this study was gathered from a thorough review of the latest papers in the literatures related to modified bituminous materials, technologies, and advances. For this purpose, the paper is presented in two principle sections. In the first part, the bitumen itself is investigated in terms of chemical structure and microstructural systems. In the second part, the paper focuses on bitumen modification from different aspects for assessing the effectiveness of the introduced additives and polymers for enhancing the engineering properties of bitumen in both paving and industrial applications. In conclusion, the knowledge obtained in this study has revealed the importance of the chemical composition of base bitumen for its modification. It can be declared that while some polymers/additives can improve one or some aspects of neat bitumen properties, they can lead to compatibility problems in storage and production. In this respect, several studies showed the effectiveness of waxes for improving the compatibility of polymers with bitumen in addition to some benefits regarding warm mix asphalt (WMA) production.

scholarly journals The Impact of Secondary Phyllosilicate Minerals on the Engineering Properties of Various Igneous Aggregates from Greece

Minerals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 329 ◽  
Author(s):  
Petros Petrounias ◽  
Panagiota Giannakopoulou ◽  
Aikaterini Rogkala ◽  
Paraskevi Lampropoulou ◽  
Eleni Koutsopoulou ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Los Angeles ◽  
Moisture Content ◽  
Total Porosity ◽  
Physicomechanical Properties ◽  
Engineering Properties ◽  
Petrographic Analysis ◽  
Rock Samples ◽  
Los Angeles Abrasion ◽  
The Impact

This paper investigates the effect of alteration on the physicomechanical properties of igneous rocks used as aggregates, from various areas from Greece. The studied lithologies include serpentinized dunites, serpentinized harzburgites, serpentinized lherzolites, metamorphic gabbros, diabases, dacites and andesites. Quantitative petrographic analysis shows that the tested samples display various percentages of secondary phyllosilicate minerals. Mineral quantification of the studied rock samples was performed by using the Rietveld method on X-ray diffraction patterns. The samples were also tested to assign moisture content (w (%)), total porosity (nt (%)), uniaxial compressive strength (UCS (MPa)) and Los Angeles abrasion test (LA (%)). The influence of secondary phyllosilicate minerals on the physicomechanical behavior of the tested samples was determined using regression analysis and their derived equations. Regression analysis shows a positive relationship between the percentage of the phyllosilicate minerals of the rocks and the moisture content as well as with the total porosity values. In mafic and ultramafic rock samples, the relationships between the secondary phyllosilicate minerals and their physicomechanical properties have shown that the total amount of the secondary phyllosilicate minerals results negatively on their physicomechanical properties. On the other hand, the low percentage of phyllosilicate minerals in volcanic rocks can’t be able to define their engineering properties.

Investigating States of Locally Manufactured Steel Reinforced Bars through Mechanical and Chemical Analysis

2020 ◽  
Vol 1013 ◽  
pp. 125-131
Author(s):  
Taha Waqar ◽  
Faramarz Djavanroodi
Keyword(s):  
Tensile Strength ◽  
Chemical Composition ◽  
Control Charts ◽  
Experimental Tests ◽  
International Standards ◽  
Accurate Information ◽  
Steel Bars ◽  
Different Types ◽  
Reinforced Steel ◽  
Manufacturing Stage

Steel reinforced bars are increasingly becoming important and demanding for their role in reinforced concrete structures for which accurate information about their properties and chemical composition is becoming essential during the manufacturing stage. The minimum required properties of the bars is determined with the aid of international standards such as ASTM A615 within Saudi Arabian manufacturers. In this work, the variation within the mechanical properties and chemical composition of various reinforced steel produced in KSA was evaluated. Experimental tests were performed on ASTM A615 Grade 60 samples to obtain their yield, tensile strength, elongation and chemical composition. Statistical analysis showed the selected properties follow different types of continuous distributions for their respective cases. Finally, control charts have been generated to identify results falling above and below 3-sigma. Results showed that 1.5%, 3% and 7.3% of samples failed to meet the minimum ASTM criteria for yield, tensile strength and weight; while less than 3% of steel bars failed to meet ASTM standards for chemical composition.

Effect of lubricating and cooling liquids on the chemical composition and physicomechanical properties of iron after rolling

1993 ◽  
Vol 29 (1) ◽  
pp. 98-103 ◽  
Author(s):  
V. V. Tikhonovich ◽  
V. V. Gorskii ◽  
L. M. Sheludchenko ◽  
A. V. Shevchenko ◽  
B. S. Shapoval ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Physicomechanical Properties

scholarly journals Evaluation and validation of technical procedure for foundry coke mechanical strength testing

2020 ◽  
Author(s):  
Bartosz Mertas ◽  
Aleksander Sobolewski ◽  
Grzegorz Rozycki
Keyword(s):  
Sample Preparation ◽  
Mechanical Strength ◽  
Physical Properties ◽  
International Standards ◽  
Strength Testing ◽  
Strength Index ◽  
Technical Procedure ◽  
Foundry Coke ◽  
Simplified Procedure ◽  
Testing And Evaluation

Abstract Foundry coke is a special type of coke with lumps size usually bigger than 100 mm. Therefore it is difficult to asses its physical properties representatively for whole lot. There exist international standards for coke sampling and testing strength index (usually Micum test). Nevertheless companies dealing with foundry coke notified problems with methodology of sampling and sample preparation for the test. Manual sampling according to ISO 18283 is very labour extensive and with connection with literally proceeding with ISO 566 gives non-representative results for foundry coke +100 mm. For this reason on the basis of these standards there was evaluated procedure for coke sampling and testing strength indexes which is more practical for plant routine use and gives more reliable results in comparison to international standard. This article presents results of work aimed at checking usability of ISO standards provisions for foundry coke testing and evaluation and validation of simplified procedure.

scholarly journals Factors That Affect the Mechanical Strength of Archaeological Wood—A Case Study of 18th-Century Wooden Water Pipes from Bóżnicza Street in Poznań, Poland

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7632
Author(s):  
Magdalena Broda ◽  
Carmen-Mihaela Popescu ◽  
Daniel Ilie Timpu ◽  
Dawid Rowiński ◽  
Edward Roszyk
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Mechanical Strength ◽  
Wood Density ◽  
Mechanical Performance ◽  
Cellulose Crystallinity ◽  
Compression Tests ◽  
Substantial Impact ◽  
Archaeological Wood

Large amounts of archaeological wood are often excavated during groundworks in cities and towns. Part of the unearthed artefacts is usually saved, conserved and then presented in museums. However, if the finding contains several similar objects, some of them could potentially be further employed for some other practical purposes. The research aimed to determine the mechanical performance of the remains of wooden water mains excavated at Bóżnicza street in Poznań, Poland and evaluate its potential usefulness for any practical purposes. First, wood density was determined along with its mechanical strength in compression. The density of archaeological wood identified as Scots pine was lower than contemporary pinewood (383 kg × m−3 vs. 572 kg × m−3); therefore, its mechanical properties in compression tests were also lower, as expected, making the wood unsuitable for any practical applications. However, the differences in modulus of elasticity and compressive strength were not justified by the differences in wood density. Further infrared spectroscopy and X-ray diffraction analyses revealed additional differences in chemical composition and cellulose crystallinity between archaeological and contemporary wood. The results indicated the decrease in carbohydrate content and cellulose crystallinity in degraded wood, which, in addition to wood density, apparently contribute to the deterioration in mechanical strength of archaeological wood. The case study of the excavated archaeological wooden pipes shows that they have historical value but are not useful for practical purposes. It also revealed that not only wood density but also its chemical composition and cellulose crystallinity level has a substantial impact on the wood mechanical properties, particularly in compression.

Sign in / Sign up

Export Citation Format

Share Document